Flood hazards in Wisconsin Active
A summary of USGS resources and data related to flooding hazards in Wisconsin.
What is a flood?
A flood occurs when relatively high water overflows the natural or artificial banks of a stream or coastal area and submerges land not normally below water level.
Why do floods occur?
In Wisconsin, floods usually are caused by one of three scenarios:
- In the summer, thunderstorms associated with slow-moving frontal systems
- In the winter, floods can occur when rain falls on snow causing rapid snowmelt
- Ice-jam floods are also a hazard during the winter
Wisconsin hydroclimatology
The principal moisture-bearing air masses for Wisconsin originate in the Gulf of Mexico (moisture can also come from air masses originating in the Pacific Ocean, but these lose most of their moisture crossing the Rocky Mountains). Lake-effect precipitation is a minor source of moisture for Wisconsin; lake-effect precipitation is most noticeable in the early winter when the cold air blowing over the unfrozen Great Lakes absorbs moisture, which then is precipitated as snow on the lake shores.
Factors that contribute to flood events in Wisconsin streams include:
- drainage area
- storage (the percentage of drainage area covered by lakes, ponds, swamps, and wetlands)
- heavy rainfall, snowfall, or snowmelt
- soil permeability of the least-permeable soil horizon
- forest and vegetation cover (the percentage of drainage area covered)
In urban areas, factors contributing to flooding include:
- drainage area
- percentage of drainage area that is impervious (parking lots, roads, rooftops)
USGS flood data
Real-time and historical information on floods in Wisconsin is available through the USGS National Water Information System (NWIS).
A map of Wisconsin gages currently at high-flow or flood conditions can be found here. Click on a site to get a summary of conditions, view the current hydrograph, or see a chart of how the current stage compares with historical peak flows and floods. Animations of current and historical high-flow and flood events (by date) are also available.
A table of current discharge measurements and historical peaks for all real-time streamgages in Wisconsin is also available. You can use the USGS WaterAlert service to receive an email or text alert if a particular streamgage exceeds a user-specified gage height or discharge value.
How the USGS contributes to flood response
During a flood, the USGS and the National Weather Service work in concert with its own precipitation data to forecast river stages and flow conditions on large rivers and their associated tributaries. The USGS collects streamflow data, the NWS collects precipitation data and combines both types of data to make flood forecasts. The USGS will continue to measure the actual height of the flood during the event.
During large, regional flood events, the USGS will deploy field crews to install temporary rapid-deployment streamgages and sensors ahead of the storm to track flooding as it happens. Some of these sensors will relay real-time information to emergency managers during the flood event, while others will be retrieved by the field crews as soon as floodwaters have receded. These hydrographers will also look for physical evidence of high-water marks left behind by the flood. Post-flood analyses allow USGS scientists determine the extent of the flood and help communities prepare for future flood events.
Below are other science projects associated with this project.
Flood frequency in Wisconsin
June 2008 floods in southern Wisconsin
Below are data or web applications associated with this project.
WaterWatch (surface water)
WaterWatch displays maps, graphs, and tables describing real-time, recent, and past streamflow conditions for the United States, including flood and droughts. Real-time information generally is updated on an hourly basis.
Surface-water data for Wisconsin
Real-time, daily, peak-flow, field measurements, and statistics of current and historical data that describe stream levels, streamflow (discharge), reservoir and lake levels, surface-water quality, and rainfall in Wisconsin. Surface-water data are collected and stored as either discrete field-water-level measurements or as continuous time-series data from automated recorders.
Below are publications associated with this project.
Changes in streamflow characteristics in Wisconsin as related to precipitation and land use
The USGS National Streamflow Information Program and the importance of preserving long-term streamgages
How does a U.S. Geological Survey streamgage work?
Flood of June 2008 in Southern Wisconsin
Flood hazards— A national threat
Large floods in the United States: where they happen and why
Flood-frequency characteristics of Wisconsin streams
Estimating magnitude and frequency of floods for Wisconsin urban streams
Flood of July 1-5, 1978 on the Kickapoo River, southwestern Wisconsin
- Overview
A summary of USGS resources and data related to flooding hazards in Wisconsin.
What is a flood?
A flood occurs when relatively high water overflows the natural or artificial banks of a stream or coastal area and submerges land not normally below water level.
Why do floods occur?
In Wisconsin, floods usually are caused by one of three scenarios:
- In the summer, thunderstorms associated with slow-moving frontal systems
- In the winter, floods can occur when rain falls on snow causing rapid snowmelt
- Ice-jam floods are also a hazard during the winter
Wisconsin hydroclimatology
The principal moisture-bearing air masses for Wisconsin originate in the Gulf of Mexico (moisture can also come from air masses originating in the Pacific Ocean, but these lose most of their moisture crossing the Rocky Mountains). Lake-effect precipitation is a minor source of moisture for Wisconsin; lake-effect precipitation is most noticeable in the early winter when the cold air blowing over the unfrozen Great Lakes absorbs moisture, which then is precipitated as snow on the lake shores.
Factors that contribute to flood events in Wisconsin streams include:
- drainage area
- storage (the percentage of drainage area covered by lakes, ponds, swamps, and wetlands)
- heavy rainfall, snowfall, or snowmelt
- soil permeability of the least-permeable soil horizon
- forest and vegetation cover (the percentage of drainage area covered)
In urban areas, factors contributing to flooding include:
- drainage area
- percentage of drainage area that is impervious (parking lots, roads, rooftops)
USGS flood data
Real-time and historical information on floods in Wisconsin is available through the USGS National Water Information System (NWIS).
A map of Wisconsin gages currently at high-flow or flood conditions can be found here. Click on a site to get a summary of conditions, view the current hydrograph, or see a chart of how the current stage compares with historical peak flows and floods. Animations of current and historical high-flow and flood events (by date) are also available.
A table of current discharge measurements and historical peaks for all real-time streamgages in Wisconsin is also available. You can use the USGS WaterAlert service to receive an email or text alert if a particular streamgage exceeds a user-specified gage height or discharge value.
How the USGS contributes to flood response
During a flood, the USGS and the National Weather Service work in concert with its own precipitation data to forecast river stages and flow conditions on large rivers and their associated tributaries. The USGS collects streamflow data, the NWS collects precipitation data and combines both types of data to make flood forecasts. The USGS will continue to measure the actual height of the flood during the event.
During large, regional flood events, the USGS will deploy field crews to install temporary rapid-deployment streamgages and sensors ahead of the storm to track flooding as it happens. Some of these sensors will relay real-time information to emergency managers during the flood event, while others will be retrieved by the field crews as soon as floodwaters have receded. These hydrographers will also look for physical evidence of high-water marks left behind by the flood. Post-flood analyses allow USGS scientists determine the extent of the flood and help communities prepare for future flood events.
- Science
Below are other science projects associated with this project.
Flood frequency in Wisconsin
Flood-frequency estimates are required at many sites for bridge and culvert design, as well as for flood-plain management and flood-insurance studies. To estimate flood frequency at ungaged locations, a network of approximately 90 crest-stage gages and more than 200 past and current continuous-record gages are used to compute regional flood-frequency equations to estimate floods at ungaged sites.June 2008 floods in southern Wisconsin
In June 2008, heavy rain caused severe flooding across southern Wisconsin. Record gage heights and streamflows occurred at 21 U.S. Geological Survey streamgages across southern Wisconsin from June 7 to June 21. - Data
Below are data or web applications associated with this project.
WaterWatch (surface water)
WaterWatch displays maps, graphs, and tables describing real-time, recent, and past streamflow conditions for the United States, including flood and droughts. Real-time information generally is updated on an hourly basis.
Surface-water data for Wisconsin
Real-time, daily, peak-flow, field measurements, and statistics of current and historical data that describe stream levels, streamflow (discharge), reservoir and lake levels, surface-water quality, and rainfall in Wisconsin. Surface-water data are collected and stored as either discrete field-water-level measurements or as continuous time-series data from automated recorders.
- Publications
Below are publications associated with this project.
Changes in streamflow characteristics in Wisconsin as related to precipitation and land use
Streamflow characteristics were determined for 15 longterm streamflow-gaging stations for the periods 1915–2008, 1915–68, and 1969–2008 to identify trends. Stations selected represent flow characteristics for the major river basins in Wisconsin. Trends were statistically significant at the 95 percent confidence level at 13 of the 15 streamflow-gaging stations for various streamflow characteristicsAuthorsWarren A. Gebert, Herbert S. Garn, William J. RoseThe USGS National Streamflow Information Program and the importance of preserving long-term streamgages
Long-term streamflow information is critical for use in several water-related areas that are important to humans and wildlife, including water management, computation of flood and drought flows for water infrastructure, and analysis of climate-related trends. Specific uses are many and diverse and range from informing water rights across state and international boundaries to designing dams and briAuthorsGlenn A. Hodgkins, J. Michael Norris, Robert M. LentHow does a U.S. Geological Survey streamgage work?
Information on the flow of rivers and streams is a vital national asset that safeguards lives, protects property, and ensures adequate water supplies for the future. The U.S. Geological Survey (USGS) operates a network of more than 9,000 streamgages nationwide with more than 500 in Texas.AuthorsDee L. LurryFlood of June 2008 in Southern Wisconsin
In June 2008, heavy rain caused severe flooding across southern Wisconsin. The floods were aggravated by saturated soils that persisted from unusually wet antecedent conditions from a combination of floods in August 2007, more than 100 inches of snow in winter 2007-08, and moist conditions in spring 2008. The flooding caused immediate evacuations and road closures and prolonged, extensive damagesAuthorsFaith A. Fitzpatrick, Marie C. Peppler, John F. Walker, William J. Rose, Robert J. Waschbusch, James L. KennedyFlood hazards— A national threat
In the late summer of 2005, the remarkable flooding brought by Hurricane Katrina, which caused more than \$ 200 billion in losses, constituted the costliest natural disaster in U.S. history. However, even in typical years, flooding causes billions of dollars in damage and threatens lives and property in every State. Natural processes, such as hurricanes, weather systems, and snowmelt, can cause flAuthorsLarge floods in the United States: where they happen and why
The spatial distribution of large gaged floods throughout the United States shows that the locations of most of the largest flows are related to specific combinations of regional climatology, topography, and basin size. Key factors include the general northward trend of decreasing atmospheric moisture, proximity to oceanic moisture sources such as the Pacific Ocean and the Gulf of Mexico, and orieAuthorsJim E. O'Connor, John E. CostaFlood-frequency characteristics of Wisconsin streams
Flood-frequency characteristics for 312 gaged sites on Wisconsin streams are presented for recurrence intervals of 2 to 100 years using flood-peak data collected through water year 2000. Equations of the relations between flood-frequency and drainage-basin characteristics were developed by multiple-regression analyses. Flood-frequency characteristics for ungaged sites on unregulated, rural streamsAuthorsJohn F. Walker, William R. KrugEstimating magnitude and frequency of floods for Wisconsin urban streams
Equations for estimating magnitude and frequency of floods for Wisconsin streams with drainage basins containing various amounts of existing or projected urban development were developed by flood-frequency and multiple-regression analyses. Multiple-regression techniques were used to develop equations for estimating flood frequencies at ungaged urban sites. The flood-frequency equations are based oAuthorsD.H. CongerFlood of July 1-5, 1978 on the Kickapoo River, southwestern Wisconsin
The Kickapoo River valley in southwestern Wisconsin had a devastating flood ($10 million estimated damages) during July 1-5, 1978. The flash flooding was caused by intense storms on June 30 through July 2. Total rainfall accumulation ranged from 5.8 inches near Ontario to 9.5 inches at La Farge. The resulting flood equaled or exceeded the largest ones recorded since the 1850 's and equaled or exceAuthorsPeter E. Hughes, J.S. Hannuksela, W.J. Danchuk